Japan's Premier Aims for Longer Stay

Kan, With Broad Backing and Eclectic Resume, Officially Ascends; Not Making Waves on Okinawa

By

Yuka Hayashi

Updated June 4, 2010 10:11 p.m. ET

TOKYO—In the 1970s, Naoto Kan was a resourceful physics graduate who invented a machine to calculate mahjong scores. In the 1990s, he was an underdog lawmaker who pilloried bureaucrats for exposing thousands of Japanese to HIV-tainted blood. Over the past decade, he has been known for his quick temper and for napping on the parliament floor.

Now, lawmakers of the ruling Democratic Party of Japan, who elevated Mr. Kan to prime...